record video and convert to flash flv format:

• I'm using the included OSX software iMovie HD (/Applications/iMovie HD).
• Open and to the left of the play button(s) is a slider control with a movie camera icon and scissors on either side. Move the slider button to the movie camera icon to turn on the built-in (iSight) macbook camera. A button appears with and on top of the video to begin recording.
• Record and edit as desired (including saving the project).
• Once saved the File > Export option is enabled, in the dialogs for this I chose to export as a quicktime compressed for web which encodes the movie as a .mov file.
• To do the (command-line) conversion: ffmpeg -i 'path/to/my_iMovie.mov' -ar 44100 -ab 96000 -f flv 'path/to/my_new_flash.flv'
• ...use the flv as desired...